/*
 * Copyright (c) 2011, Nikolaus Moll
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * * Neither the name of the gradecalculator.net nor the
 *   names of its contributors may be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */
package net.gradecalculator.plugin.util;

import java.io.File;
import java.io.FilenameFilter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;

import net.gradecalculator.plugin.importer.interfaces.ICommonImportPlugin;
import net.gradecalculator.plugin.loader.PluginLoader;
import net.gradecalculator.plugin.loader.exceptions.PluginException;

public final class ImportPluginUtil {
	
	private static final String RESOURCE = "importplugin";
	
	public static class PluginDescriptor implements Comparable<PluginDescriptor> {
		private final String classname;
		private final String name;
		private final String version;
		private final ICommonImportPlugin plugin;
		
		public PluginDescriptor(final File classfile)
		{
			classname = getClassName(classfile);
			plugin = loadPlugin(classfile);
			name = plugin.getName();
			version = plugin.getVersion();
		}

		public String getClassname() {
			return classname;
		}

		public String getName() {
			return name;
		}

		public String getVersion() {
			return version;
		}
		
		public ICommonImportPlugin getPlugin()
		{
			return plugin;
		}
		
		private String getClassName(final File classfile)
		{
			final String filename = classfile.getName();
			final int index = filename.indexOf(".jar");
			if (index < 0) {
				throw new PluginException("Invalid plug-in filename", null);
			}

			return filename.substring(0, index);
		}
		
		private ICommonImportPlugin loadPlugin(final File classfile)
		{
			//final String className = "net.miblounge.gradecalculator.importer." + classname;
			return (ICommonImportPlugin)PluginLoader.getPluginByResource(classfile, RESOURCE);
		}

		@Override
		public int compareTo(final PluginDescriptor o) {
			return name.compareTo(o.name);
		}
	}
	
	private static List<PluginDescriptor> plugins = new ArrayList<PluginDescriptor>();

	private static List<Throwable> exceptions = new LinkedList<Throwable>();
	
	
	private ImportPluginUtil()
	{
	}
	
	public static void initialize()
	{
		exceptions.clear();
		plugins.clear();
		final File importerDirectory = new File("plugins/importer");
		final FilenameFilter filter = new FilenameFilter() {
            @Override
			public boolean accept(final File dir, final String name) {
                return name.endsWith(".jar");
            }
        };

        final File[] pluginlist = importerDirectory.listFiles(filter);
        if (pluginlist == null) {
        	return;
        }
        for (File pluginFile : pluginlist) {
    		try {
        		plugins.add(new PluginDescriptor(pluginFile));
    		} catch (final PluginException e) {
    			exceptions.add(e);
	        }
		}
        
        // TODO log exception
	}
	
	public static List<PluginDescriptor> getPlugins()
	{
		final List<PluginDescriptor> result = new ArrayList<PluginDescriptor>(plugins);
		Collections.sort(result);
		return result;
	}

	public static List<Throwable> getExceptions()
	{
		return exceptions;
	}
}
